title: Laxative abuse as a cause for ammonium urate renal calculi.
abstract: Nine women with laxative abuse and predominantly ammonium urate renal calculi underwent metabolic studies to identify common chemical abnormalities and determine pathophysiology. The 24-hour urine studies demonstrated marked decreases in volume (902 cm.3), sodium (28 mEq.), citrate (116 mg.) and potassium (21 mEq.). A significant elevation in ammonium urate supersaturation was found compared to control subjects when studied by the computer model EQUIL 2. Of the patients 7 had 1 or more urine specimens positive for phenolphthalein. Gastrointestinal loss of fluid and electrolytes allowed for chronic extracellular volume depletion. Intracellular acidosis was present as judged by low urinary citrate and potassium. The fact that the ion product for ammonium urate is increased significantly compared to controls reflects the stated pathophysiological changes. Laxative abuse should be suspected whenever a woman has an ammonium urate renal calculus in sterile urine.
authors.affiliation: Department of Urology, Methodist Hospital of Indiana, Indianapolis.
authors.forename: W H
authors.initials: WH
authors.lastname: Dick
authors.forename: J E
authors.initials: JE
authors.lastname: Lingeman
authors.forename: G M
authors.initials: GM
authors.lastname: Preminger
authors.forename: L H
authors.initials: LH
authors.lastname: Smith
authors.forename: D M
authors.initials: DM
authors.lastname: Wilson
authors.forename: W L
authors.initials: WL
authors.lastname: Shirrell
mesh_terms: D000328:Adult; D002400:Cathartics; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000032:analysis / Q000139:chemically induced* / Q000652:urine; D008875:Middle Aged; D010635:Phenolphthaleins / Q000009:adverse effects; D012651:Self Medication / Q000009:adverse effects; D019966:Substance-Related Disorders / Q000150:complications*; D014527:Uric Acid / Q000032:analysis*; D014883:Water-Electrolyte Imbalance / Q000139:chemically induced / Q000652:urine
chemical_list: D002400:Cathartics; D010635:Phenolphthaleins; D014527:Uric Acid